A Versatile Catalyst for Intermolecular Direct Arylation of Indoles with Benzoic Acids as Arylating Reagents
作者:Jun Zhou、Peng Hu、Min Zhang、Shijun Huang、Min Wang、Weiping Su
DOI:10.1002/chem.201000529
日期:2010.5.25
(Pd(TFA)2/Ag2CO3/propionic acid) both electron‐rich and ‐deficient benzoicacids serve as arylating reagents for the direct functionalization of a wide rage of indoles by a combination of decarboxylation and CH bond activation. Depending on the nature of the benzoicacids, the reaction occurs selectively at either the C2‐ or C3‐position of indoles, which may arise from two different catalytic pathways (see scheme;
耦合在一起:借助通用的催化剂体系(Pd(TFA)2 / Ag 2 CO 3 /丙酸),富电子和不足的苯甲酸都可以作为芳构化试剂,通过以下两种方法的结合直接将多种吲哚官能化脱羧和CH键活化。根据苯甲酸的性质,该反应选择性地发生在吲哚的C2或C3位置,这可能是由两种不同的催化途径引起的(请参阅方案; TFA =三氟乙酸盐)。
Rhodium-Catalyzed β-Selective Oxidative Heck-Type Coupling of Vinyl Acetate via C–H Activation
作者:Hui-Jun Zhang、Weidong Lin、Feng Su、Ting-Bin Wen
DOI:10.1021/acs.orglett.6b03244
日期:2016.12.16
An efficient Rh(III)-catalyzed direct ortho-C–H olefination of acetanilides with vinylacetate was developed. This protocol provides a straightforward pathway to a series of (E)-2-acetamidostyryl acetates, giving access to indole derivatives following a simple hydrolysis/cyclization process.
Cu(II)-Catalyzed Direct and Site-Selective Arylation of Indoles Under Mild Conditions
作者:Robert J. Phipps、Neil P. Grimster、Matthew J. Gaunt
DOI:10.1021/ja801767s
日期:2008.7.1
We have developed a new site-selective Cu(II)-catalyzed C-H bond funtionalization process that can selectively arlate indoles at either the C3 or C2 position under miled conditions. The scope of arylation process is broad and tolerates broad functionality on both indole and aryl unit, which makes it amenable to further elaboartion. The mechanism of the arylation reaction is proposed to proceed via a Cu(III)-aryl that undergoes intial addition at the C3 position of the indole motif. We speculate that site of indole arylation arises through a migration of the Cu(III)-aryl group of C3 to C2, and this can be controlled by the nature of the group on the nitrogen atm; free (NH)-and N-alkylindoles deliver the C3-arylated product, whereas N-acytylindoles affored the C2 isomer, both with excellent yield and selectivity.
Transition Metal-Free Regioselective C-3 Amidation of Indoles with<i>N</i>-Fluorobenzenesulfonimide
作者:Hai-Hong Liu、Yi Wang、Guojun Deng、Luo Yang
DOI:10.1002/adsc.201300767
日期:2013.11.25
AbstractA direct transition metal‐free regioselective C‐3 amidation of indoles has been developed with the commercially available N‐fluorobenzenesulfonimide (NFSI) as the amino source under external oxidant‐free conditions. This amidation requires only a catalytic amount of base and exhibits excellent functional group tolerance and regioselectivity. The C‐3 regioselectivity was proposed to realize by a free radical mechanism.magnified image